The exponential growth of the Internet and World Wide Web required substantially scalable data delivery solutions for ever increasing cable, DSL and other wireline broadband networks. Mirroring or replication of some sites at different geographical locations was not adequate to meet the exponential growth of data traffic. Content Delivery Networks (CDN) emerged to address the scalability and performance problems posed by ever-increasing broadband subscribers and traffic. CDNs use a variety of techniques including web caching to reduce bandwidth requirements, reduce server load, and improve the user response times for content stored in the cache. Specifically, web caching refers to the storing of copies of web documents such as HTML pages, video, image and other multimedia objects in a distributed cache; subsequent requests for web content may be satisfied from the cache if certain conditions are met. CDNs achieve reduced round trip times for interactive web-browsing sessions by bringing content closer to the user. CDNs may also pre-fetch and store content in their caches before the actual request is made in order to increase the cache hit rate
Some wireline providers also deploy web caches in their networks in order to reduce their Internet bandwidth needs and enhance the web browsing experience for their subscribers as shown in FIG. 1a. 
Content caching devices, or web-caches, that cache frequently viewed web pages, pictures and multi-media content are traditionally deployed in the internet for reducing transport latencies, and reducing download times for heavily accessed content across the internet. Similarly, web-proxies/caches are also deployed at enterprise sites to cache frequently used Internet web-content within the enterprise network. Such devices are currently used within mobile wireless networks, with certain limitations.
FIG. 1a shows the network elements in an exemplary wireline network, as is commonly found today. Multiple user devices 7 attach to a local network medium, such as DSL, cable, or other internet connection. The local DSL or cable backhaul 8 connects to the metro network 9, such as through a DSLAM (DSL Access Multiplexer) or CMTS (Cable Modem Terminal System) 11. Routers 2 are used to move packets through the internet 12 in accordance with their source and destination addresses. Servers 14 host websites that contain the original content for those websites. However, in an effort to save time and network traffic, web caches 1 or other similar devices are used to store replicas of this original content. Thus, throughout the internet, there may be one or more web caches 1 that provide the requested data without having to burden server 14. In large metro areas, it is also common to introduce cache servers 1 in the metro network 9.
Caching devices can also be used in mobile wireless network, for example, a 3G/UMTS network 20. The wireless network includes a Radio Access Network (RAN) and a Core Network (CN). A typical wireless network is shown in FIG. 1b. 
The GGSN 3 (Gateway GPRS Service Node) connects the mobile wireless network to the IP Core Network. The Gateway GPRS Support Node (GGSN) 3 is a main component of the GPRS (General Packet Radio Service) network. The GGSN 3 is responsible for compatibility between the GPRS network and external packet switched networks, such as the Internet and X.25 networks.
When viewed from an external network, the GGSN 3 appears as a router to a sub-network, because the GGSN 3 hides the GPRS infrastructure from the external network. When the GGSN 3 receives data addressed to a specific user, it checks if the user is active. If it is, the GGSN 3 forwards the data to the SGSN 4 serving the mobile user. However if the mobile user is inactive, the data are discarded, or a paging procedure is initiated to locate and notify the mobile device. For data originated within the GPRS network, the GGSN 3 routes these mobile-originated packets to the correct external network.
The GGSN 3 converts the GPRS packets coming from the SGSN 4 into the appropriate packet data protocol (PDP) format (e.g., IP or X.25) and sends them out on the corresponding packet data network. For incoming packets, the PDP addresses are converted to the GSM address of the destination user. The readdressed packets are then sent to the responsible SGSN 4. In order to accomplish this function, the GGSN 3 stores the current SGSN address of the user and its associated profile in its location register. The GGSN 3 is responsible for IP address assignment and is the default router for the connected user equipment (UE) 7. The GGSN 3 also performs authentication functions.
A Serving GPRS Support Node (SGSN) 4 is responsible for the delivery of data packets from and to the mobile stations within its geographical service area. Its tasks include packet routing and transfer, mobility management (attach/detach and location management), logical link management, and authentication and charging functions. The location register of the SGSN 4 stores location information and user profiles of all GPRS users registered with this SGSN 4.
The Radio Network Controller (or RNC) 5 is a governing element in the radio access network and is responsible for controlling the Node Bs 6 that are connected to it. The RNC 5 carries out radio resource management, some of the mobility management functions and is the point where encryption is done before user data is sent to and from the mobile. The RNC 5 connects to the SGSN (Serving GPRS Support Node) 4 in the Packet Switched Core Network.
Node B 6 is a term used to denote the base transceiver station (BTS) in the UMTS/3GPP Architecture. As in all cellular systems, such as GSM, Node B (or BTS) 6 contains radio frequency transmitter(s) and the receiver(s) used to communicate directly with the user equipment, which move freely around it.
The user equipment (UE) 7 comprises all user equipment, including handsets, smart phones and computing equipment.
Radio Access Networks (RANs), such as in GSM/GPRS, 3G/UMTS/HSDPA/HSUPA, LTE, CDMA network etc., have their own private networks (PLMN) and interconnect to the Internet/IP networks through gateway devices (GGSN in GSM/GPRS, 3G/UMTS/HSDPA/HSUPA, and PDSN in CDMA). Content caches are typically deployed outside of the RAN as shown in FIG. 1b. However, content caches are not deployed in the RAN between the Wireless Base Station 6 and GGSN 3 or PDSN (in a CDMA Network).
One reason for this is, while the user application payloads are TCP/IP, those payloads are embedded within Radio Access Network Protocols that are specific to the specific RAN. Thus, within the RAN, application payloads are not directly visible for performing content-aware caching and other optimizations. The RAN network 20 is deployed as a transport network that transports user IP traffic (Bearer IP traffic) using either ATM or IP transports. Regardless of the type of transport, the RAN network transports the user payloads in per user/per service tunnels. Such tunnels are terminated within the PDSN or GGSN 3, which forwards the bearer IP traffic to the public IP network using IP forwarding rules. Thus in the prior art deployments, the RAN network is content un-aware.
Therefore, it would be beneficial if caching devices could be made to operate within the RAN. This would allow more efficient access to content, minimize internet traffic and transfer times. Furthermore, network elements in the RAN are more localized, with lower capacity (throughput and simultaneous users). This facilitates insertion of a lower capacity caching and content-aware optimization device. Such a network would better scale as it facilitates distributed deployment. A method and system to allow caching within a RAN would be advantageous.